Electric resistance.



R. C. HARRIS,

ELECTRIC RESISTANCE.

APPLIGATXON TILED r1112. 18, 1913.

1,006,655 I Patented Oct. 24 1911. Q 2 SHEETS-SHEET 1.

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ELECTRIC RESISTANCE,

APPLIQMIOH FILED FEB.18,1911.

Patented Oct. 24, 2 SHEETS-$11331 WITNESIJES wwaw A) INVENTORROBERT-614A R LES'HARRIfi.

' UNITED'STATES PATENT OFFICE.

ROBERT CHARLES HARRIS, F GATESI-IEAD, ENGLAND, ASSIGNOR '10 CLARKECHAIR- MAN AND COMPANY LIMITED, OF GATESHEAD, ENGLAND.

ELECTRIC nnsrs'rmfcn.

Specification of Letters Patent.

Application filed February 18, 191}. Serial No. 609,460.

sup 'lorted by but one binding rod and re-' qulring no slotted holds orspecial bends a nsi on.

ie invention the strip is :ies of holes, pitched apart and then bent toa form that the into alinement and lance 'llllt having stable loopedalternately at opporod that extends terribly the holes in aced and thedistance l the holes thereby ops nt equal length. ar the holes might beuneqn. s to enable loops at one side to be made longer than loops on theother side thereof, or to enable both. long and short loops to bearranged at each side of the red, the long loops alternating with theshort loops. In other cases the holes could be arranged to graduallyincrease in pitch until the center is reached, and then to decrease. Theresultantunit would in this case have a circular form. The binding rodmay be made of insulating material or of metal covered with a suitableinsulator. The loops of the strip of the unit may be separated invarious ways. Thus a single insulating washer may be placed between eachadjacent pair of faces it's-of the strip. Or a number of washers may beplaced between such pairs of faces, in which case one washer need alonebe of insulating material. In the accompanying drawings Figure 1 is aside elevation of the two end portions of one form of resistance unitaccording to the invention. Fig. 2 is an end elevation of the left handportion of Fig. 1 and Fig. 3 is a central horizontal sectioncorresponding to Fig. 1. Fig. 4 is'a. central hori- \t in .still furthermodifications.

zontal section of a portion of a modified form of-resistance unit andFig. 5 is a similar view illustrating a further modification. Figs. 6and 7 are views similar to Fig. 3 of Fig. 8 shows a portion of stripmaterial for use in units shown in the preceding figures.

In the example according to Figs. 1 to 3,

Patented Oct. 24., 1911.

A is the strip, corrugated longitudinally at b and r: to within a shortdistance of the to previous to oorrugationbeing punched with holes B asshown in Fig, 8. C is the binding rod of metal covered with suitableinsulating material D. E are insulating washers and F metal washersplaced between the folds of the strip. H are the terminals serving tosupport the. unit. L are nuts and m spring washers serving to clamp thestrip, washers and terminals together.

- Fig. illustrates a modification wherein electrical connection is madewith the unit intermediate of its length, G being a conductor orterminallocated in contact with one of the metal 'asncrs F. As anothermode of effecting connection with the strip of the unit intermediate ofits length, suitable Wnen the binding rod is of metal propcrlyinsulated. a collar may be formed on or fixed to the binding rod at therequired position so as to make contact. with the strip, there beingthen a terminal at each end of the strip and a terminal connected to thebinding rod, the'current passing through part of the latter.

A compound washer for carrying out the foregoing modification isillustrated in Fig. 5 where J is a collar split, preferably at onepoint, and having an exterior taper. K is a complete collar having acorresponding interior taper, the said collars when clamped togetherwith the remaining elements causing good electrical contact. to be madewith the binding rod 0. P represents a. conductor or terminal inelectrical connection with the clamping rod G.

In some cases in lieu of having a. terminal arranged at opposite ends ofthe strip, one end of the latter can, as shown in Fig. 6 be clamped asby nuts Q to the rod C, one terminal H being employed in directelectrical connection with the opposite end of the strip and anotherterminal H located .adjacent to the terminal H in electrical conaid fggcflowing the whole length of the binding r Fig. 7 shows a furthermodification in which in lieu of the nuts Q, one such nut Q, and collarsJ and K as described with reference to Fig" are employed for connectingthe end of the strip to the rod 0.

The form of the washers for separating the portions of the strip willdepend upon the nature of the corrugations in the strip.

What I claim is v 1.. A resistance unit comprising a'metal strip havingperforations spaced throughout its length, and folded intermediate ofthe perforations so as to bring the latter into v aline-ment, and asupport extending through said perforations.

'2. A resistance unit comprising a metal strip having perforationsspaced throughout its length and folded intermediate of the perforationsso as to bring the latter into alinement, an insulating rod extendingthrough said perforations and insulating devices disposed between theseveral. loops formed by the folds in thestrip.

3. A resistance unit comprising a. metal strip having perforationsspaced throughout its length and folded intermediate of the perforationsso as to bring the latter into alinement, an insulating rod extendingthrough said perforations, a pair of metal washers threaded on the rodbetween each loop formed by the folds in the strip, an insulating washerbetween each pair of metal washers and means upon the rod for clampingthe metal strip and washers together.

4. A resistance unit comprising a metal strip having perforations spacedthroughout its length and folded intermediate of the perforations so asto bring the latter into alinement, an insulating rod extending throughsaid perforations, insulators disposed between the sevaral loops formedby the folds in the strip, means clamping the strip and washers togetherupon the rod and a terminal in electrical contact with the stripintermediate of its length. l

5. A resistance unit comprising a metal strip having perforations spacedthroughout its length and folded intermediate of the perforations so asto bring the latter into alinement, an insulating rod extending fiiroughsaid erforations, a pair of metal ,ashers threa ed on the rod betweeneach .Toop formed by the folds in the strip, an insulating washerbetween each pairtof metal washers a terminal in electrica contact withone of said metal Washers and means 11 n the rod for clamping the metalstrip'and washer embracing the rod and in electrical connectiontherewith; a clamping ring en circling the said washer and in electricalcontact with both the ring and one portion of the strip intermediate ofits length, insulating devices separating the several loops formed bythe folds in the strip, devices on the rod for clamping the metal stripand washers together and a terminal in electrical connection with therod.

. 7. A resistance unit comprising a strip of metal punched with holes atpredetermined intervals, corrugated longitudinally to within a shortdistance of points midway between 'the holes and folded at such pointsto bring the holes into alinement and form stable loop-like portionsextending alternately in opposite directions from the axis common to thealined holes.

8. In a resistance unit, the combination with a metal clamping rod, astrip of metal, folded into loops, threaded on said rod, and aninsulating sleeve separating the strip from the rod, of a compoundWasher adapted to place the rod in electrical connection with the strip.

9. In a resistance unit, the combination with a metal clamping rod, astrip of metal, folded into loops,-threaded on said rod, and aninsulating sleeve separating the strip from the rod, of a compoundwasher adapted to place the rod in electrical conncction with the strip,a terminal in electrical connection with. the rod at one end of,the unitand a terminal adjacent to the other terminal insulated from the rod andin electrical connection with the strip.

Signed at Gateshead this second day of February 1911.

ROBERT CHARLES HARRIS.

'VVitnesses:

' TnoMAs W. THOMPSON,

CHARLES P. YOUNG.

